How Many Steps a Day Keep the Grim Reaper at Bay?

Walking at least 8,000 steps even just a couple days per week was linked with a lower risk of death, a cohort study of U.S. adults suggested.

When compared with people who never clocked 8,000 steps in a regular week, risk of all-cause mortality at 10 years was lower among those who took 8,000 steps or more 1 to 2 days per week (adjusted risk difference [aRD] -14.9%, 95% CI -18.8 to -10.9), reported Kosuke Inoue, MD, PhD, of Kyoto University in Japan, and colleagues.

This risk was even lower among those who hit 8,000 steps or more 3 to 7 days per week (aRD -16.5%, 95% CI -20.4 to -12.5), the group noted in JAMA Network Open.

"The estimated association was also robust to using different thresholds between 6,000 and 10,000 steps for the daily step counts," Inoue and team wrote. "Our study findings suggest that for those individuals who face difficulties in exercising regularly (e.g., due to work and/or family obligations), achieving recommended daily steps only a couple days per week can have meaningful health benefits."

In addition, 10-year cardiovascular mortality risk was lower among those who took 8,000 steps or more 1 to 2 days per week (aRD -8.1%, 95% CI -11.8 to -4.4) and 3 to 7 days per week (aRD -8.4%, 95% CI -12.5 to -4.4) compared with 0 days per week.

"The protective association plateaued when individuals took sufficient daily steps for 3 days or more," Inoue and colleagues noted.

In an accompanying commentary, James Sawalla Guseh, MD, of Massachusetts General Hospital and Harvard Medical School in Boston, and Jose Figueroa, MD, MPH, of Harvard T.H. Chan School of Public Health in Boston, pointed out that this lends support to the idea of the "weekend warrior."

"The results highlight the possible feasibility of an 8,000-step goal achieved twice a week as a potential minimal physical activity threshold that could be accessible and achievable," they wrote. "In an era where physical inactivity is a widespread epidemic, new and simpler approaches to physical activity guidance, such as step-based goals, may be more attractive and motivating for the public."

However, they noted that "the body of evidence for sporadic activity is not as robust as the evidence for sustained and regular aerobic activity."

Inoue and colleagues used National Health and Nutrition Examination Survey data from the 2005 to 2006 cycle for the analysis. They included 3,101 individuals ages 20 and older in the final analysis, all of whom had step count data available, which was obtained from an accelerometer during waking hours for 7 consecutive days.

Mean age was 50.5, and 51% were women. About half were white, 21.5% were Black, and 23.7% were Hispanic. Over 10-year follow-up, 14.2% of participants died from any cause and 5.3% died from cardiovascular causes, according to ICD-10 codes.

About 63% of all participants hit 8,000 steps or more at least 3 days per week, while 17.2% hit this goal 1 or 2 days per week; 20.4% didn't reach this goal any day of the week.

Nearly 30% of those with cardiovascular disease at baseline didn't hit the step goal any day of the week, and only 5.8% hit the goal at least 3 days per week. A similar trend was seen for those with diabetes or hypertension at baseline.

Those clocking more steps tended to be younger, men, Hispanic, insured, married, and never smokers.

However, in stratified analyses, even participants ages 65 and older experienced lower 10-year all-cause mortality risk when they took 8,000 steps or more 1 to 2 days per week (aRD -19.9%, 95% CI -30.8 to -8.9) and 3 to 7 days per week (aRD -27.7%, 95% CI -36.5 to -19.0) versus 0 days per week.

While men and women both had protective benefits from walking, men saw slightly larger magnitudes of protection with walking 8,000+ steps at least 3 days a week (aRD -23.8% vs -12.2% for women).

Guseh and Figueroa pointed out a few limitations to the study, including its observational design and possible selection bias.

Comment